I think we're not about to do any other soft fork upgrades in the next 12 months anyway. And leaving holes open of that nature isn't worth it in current context.
That is most likely the case but I’m not enthused about getting into a bare knuckle brawl for just a temporary change. Removing the unused witness stuff from the soft fork scope is strategically useful as it removes a piece of FUD from our adversaries and puts Core in an awkward position vis a vis policy if and when scammers start using that for their spam.